src/lib/ffmpeg.ts

import ffmpeg from "ffmpeg-static";
import ffprobe from "ffprobe-static";
import fluent_ffmpeg, { type FfprobeData } from "fluent-ffmpeg";
import createError from "http-errors";
import { Context } from "elysia";
import { T_Probe } from "./types";
import { NS_misc } from "./misc";
import { NS_promise } from "./promise";
import { NS_error } from "./error";
import UserAgent from "user-agents";
import { exec, execSync } from "node:child_process";

const APP_ENV = process.env.APP_ENV;
const FFMPEG_V = process.env.FFMPEG_V;
const FFPROBE_V = process.env.FFPROBE_V;
const CPU_0V1 = process.env.CPU_0V1;

const is_prod =
  process.env.NODE_ENV === "production" ||
  APP_ENV === "prod" ||
  APP_ENV === "pre_prod";

const ffmpeg_path = is_prod ? "ffmpeg" : ffmpeg || "ffmpeg";
const ffprobe_path = is_prod ? "ffprobe" : ffprobe.path || "ffprobe";

// const ffmpeg_path = ffmpeg || "";
// const ffprobe_path = ffprobe.path;
// const ffmpeg_path = "/usr/local/bin/ffmpeg";
// const ffprobe_path = "/usr/local/bin/ffprobe";

fluent_ffmpeg.setFfmpegPath(ffmpeg_path);
fluent_ffmpeg.setFfprobePath(ffprobe_path);

let hw_encoder: any = await get_hardware_encoder();
hw_encoder =
  typeof hw_encoder !== "string" || !hw_encoder.trim()
    ? "libx264"
    : hw_encoder.trim();
// hw_encoder = "libx264";

console.log(`🚀 Using hardware encoder: ${hw_encoder}`);

const TIMEOUT_MS = 20_000; // probe + transcode timeout
const PROBE_TIMEOUT_MS = 30_000; // probe + transcode timeout

function getFfmpegEncoderConfig() {
    try {
        // Quick 0.5-second test to see if Intel QSV hardware initializes successfully
        execSync(`${ffmpeg_path} -y -f lavfi -i testsrc=duration=0.5 -c:v h264_qsv -f null -`, { 
            stdio: 'ignore',
            timeout: 2000 // 2 second safety timeout
        });
        
        // QSV is active and working
        return {
            videoCodec: 'h264_qsv',
            preset: '7', // QSV fastest speed numeric preset
            extraFlags: []
        };
    } catch (error) {
      console.error({error});
        // Fallback to CPU software encoding if hardware check fails
        return {
            videoCodec: 'libx264',
            preset: 'ultrafast', // Software fastest speed preset
            extraFlags: ['-crf', '23'] // CRF is ideal for libx264
        };
    }
}

function get_hardware_encoder() {
  return new Promise((resolve) => {
    // We wrap ffmpeg path in quotes in case there are spaces in the path
    const checkCmd = `"${ffmpeg_path}" -encoders | grep -E "nvenc|qsv|vaapi"`;

    exec(checkCmd, (error, stdout) => {
      if (error || !stdout) {
        return resolve(null);
      }

      const output = stdout.toLowerCase();
      if (output.includes("nvenc")) return resolve("h264_nvenc");
      if (output.includes("qsv")) return resolve("h264_qsv");
      if (output.includes("vaapi")) return resolve("h264_vaapi");

      resolve(null);
    });
  });
}

async function F_probe_v1(arg0: {
  playback_headers?: Record<string, any> | null;
  playback_url: URL;
  context?: Context;
}) {
  const { playback_headers, playback_url, context } = arg0;

  const [E_, R_] = await NS_promise.F_catch_promise({
    promise: NS_misc.F_test_connection({
      url: playback_url,
      headers: playback_headers
    })
  });

  if (E_) {
    const { status, message } = NS_error.F_collect_error_status_n_message({
      ERR: E_
    });

    if (["522", "510", "502", "503", "404", "410"].includes(`${status}`))
      throw E_;
  }

  const command = fluent_ffmpeg();

  // Add network options
  command.addOption("-timeout", (30 * 1_000_000).toString()); // 30 seconds
  command.addOption("-reconnect", "1"); // Auto-reconnect
  command.addOption("-reconnect_streamed", "1");
  command.addOption("-reconnect_delay_max", "5");
  command.addOption("-multiple_requests", "1"); // For HLS/DASH
  // command.addOption("-user_agent", "Mozilla/5.0");

  if (is_prod && FFPROBE_V === "latest") {
    command.addOption("-allowed_segment_extensions", "ALL"); // Explicitly allow 'none' and 'jpg' in addition to ALL "ts,m4s,jpg,jpeg,none,ALL"
    command.addOption("-allowed_extensions", "ALL");
    command.addOption("-hls_flags", "+nocheck_content_type"); // This tells the HLS demuxer to stop validating extensions against content
    command.addOption("-extension_picky", "0");
    command.addOption("-protocol_whitelist", "file,http,https,tcp,tls,crypto");
    command.addOption("-strict", "experimental");
  }

  command.input(playback_url.href);

  if (playback_headers && Object.keys(playback_headers).length > 0) {
    const header_string = Object.entries(playback_headers)
      .map(([k, v]) => `${k}: ${v}`)
      .join("\r\n");

    command.addOption("-headers", header_string);
  }

  command.addOption("-v", "error");
  command.addOption("-probesize", "5000000");
  command.addOption("-analyzeduration", "5000000");
  command.addOption(
    "-show_entries",
    "format=duration,size,format_name:stream=index,codec_type,codec_name,height,width,bit_rate"
  );
  command.addOption("-show_entries", "stream_tags=language");
  command.addOption("-of", "json");

  const metadata = await new Promise<FfprobeData>((resolve, reject) => {
    command.ffprobe((err, data) => {
      if (err) {
        console.error("[PROBE ERROR]:", err.message);

        // Better error message
        if (err.message.includes("resolve hostname")) {
          return reject(
            createError(
              502,
              `Cannot resolve hostname: ${playback_url.hostname}. Check network/DNS.`
            )
          );
        }
        if (err.message.includes("I/O error")) {
          return reject(
            createError(
              502,
              `Network I/O error: Cannot reach ${playback_url.href}`
            )
          );
        }

        return reject(createError(500, `Probe failed: ${err.message}`));
      }
      resolve(data);
    });
  });

  const streams = metadata.streams;

  let hasSubs = false;

  const audioStreams: any[] = [];
  const videoStreams: any[] = [];
  const subStreams: any[] = [];

  // Single pass through streams
  for (const stream of streams) {
    if (stream.codec_type === "video") {
      // if (!videoStream) videoStream = stream;
      videoStreams.push(stream);
    } else if (stream.codec_type === "audio") {
      // if (!audioStream) audioStream = stream;
      audioStreams.push(stream);
    } else if (stream.codec_type === "subtitle") {
      hasSubs = true;
      subStreams.push(stream);
    }
  }

  const videoStream = streams.find((s) => s.codec_type === "video");
  const audioStream = streams.find((s) => s.codec_type === "audio");

  // --- Track Selection Logic ---

  // Find English Audio or default to first audio (index 0 of audio type)
  const englishAudio = audioStreams.find((s) => s.tags?.language === "eng");
  const audioIndex = englishAudio?.index ?? audioStreams[0]?.index ?? 1;

  // Find English Subtitles or default to first subtitles
  const englishSub = subStreams.find((s) => s.tags?.language === "eng");
  const subIndex = englishSub?.index ?? subStreams[0]?.index ?? null;

  // Find 720p video or highest resolution
  const target720 = videoStreams.find((s) => s.height === 720);
  const bestVideo =
    target720 ||
    videoStreams.reduce(
      (best, current) =>
        (current.height || 0) > (best.height || 0) ? current : best,
      videoStreams[0]
    );

  const bestVideoIndex = bestVideo?.index;

  const probe_data: T_Probe = {
    videoCodec: videoStream?.codec_name || "none",
    audioCodec: audioStream?.codec_name || "none",
    hasSubs,
    duration: metadata.format.duration,
    size: metadata.format.size,
    format_name: metadata.format.format_name,
    audioIndex,
    subIndex,
    bestVideoIndex
  };

  return {
    probe_data,
    metadata
  };
}

async function F_probe_v2(arg0: {
  playback_headers?: Record<string, any> | null;
  playback_url: URL;
  playback_type?: string;
  context?: Context;
  _log?: boolean;
  file_mode?: {
    path: string;
  };
}) {
  const { playback_url, context, file_mode } = arg0;
  let { playback_headers, _log } = arg0;

  if (typeof _log !== "boolean") {
    _log = true;
  }

  if (!playback_headers) {
    playback_headers = {};
  }

  if (!playback_url && !file_mode?.path) {
    throw Error("Invalid playback endpoint");
  }

  if (playback_url && !file_mode?.path) {
    const [E_, R_] = await NS_promise.F_catch_promise({
      promise: NS_misc.F_test_connection({
        url: playback_url,
        headers: playback_headers
      })
    });

    if (E_) {
      const { status, message } = NS_error.F_collect_error_status_n_message({
        ERR: E_
      });

      if (
        ["522", "510", "502", "503", "404", "410", "429"].includes(`${status}`)
      )
        throw E_;
    }
  }

  const controller = new AbortController();

  function kill_controller() {
    controller.abort();
    console.log("[CONTROLLER] Request aborted");
  }

  const t = setTimeout(() => kill_controller(), PROBE_TIMEOUT_MS);

  const abort_signal = context?.request.signal;

  /* forward browser abort -> our controller */
  if (abort_signal) {
    if (abort_signal.aborted) {
      kill_controller();
    } else {
      abort_signal.addEventListener(
        "abort",
        () => {
          kill_controller();
        },
        {
          once: true
        }
      );
    }
  }

  console.log("\n", "PING PROBE NOW", "\n");

  const command = [ffprobe_path, "-v", "error"];

  command.push("-probesize", "5000000"); // Limit probe size to 5MB (default is 5MB, but explicit)
  command.push("-analyzeduration", "5000000"); // Analyze only 5 seconds (default is 5s)
  command.push(
    "-show_entries",
    "format=duration,size,format_name:stream=index,codec_type,codec_name,height,width,bit_rate"
  ); // Show format and stream information
  command.push("-show_entries", "stream_tags=language"); // Get language tags
  command.push("-of", "json"); // Output format as JSON

  if (is_prod && FFPROBE_V === "latest") {
    command.push("-allowed_segment_extensions", "ALL"); // Explicitly allow 'none' and 'jpg' in addition to ALL "ts,m4s,jpg,jpeg,none,ALL"
    command.push("-allowed_extensions", "ALL");
    command.push("-hls_flags", "+nocheck_content_type"); // This tells the HLS demuxer to stop validating extensions against content
    command.push("-extension_picky", "0");
    command.push("-protocol_whitelist", "file,http,https,tcp,tls,crypto");
    command.push("-strict", "experimental");
  }

  // Add headers if needed
  function add_headers_if_needed() {
    // Helper to find a header key ignoring case
    const ua = NS_misc.F_get_obj_kv({
      name: "User-Agent",
      obj: playback_headers
    });

    if (!ua) {
      try {
        // Generate a realistic desktop Chrome User-Agent
        const userAgent =
          UserAgent.random({ deviceCategory: "desktop" }) || new UserAgent();

        if (!playback_headers) {
          playback_headers = {};
        }

        playback_headers["User-Agent"] = userAgent.toString();
      } catch (err: any) {}
    }

    if (playback_headers && Object.keys(playback_headers).length > 0) {
      const ua = NS_misc.F_get_obj_kv({
        name: "User-Agent",
        obj: playback_headers
      });
      const ref = NS_misc.F_get_obj_kv({
        name: "Referer",
        obj: playback_headers
      });

      // Separate specific flags for better reliability (Pass Headers to Sub-demuxers)
      // if (ua) command.push("-user_agent", ua);
      // if (ref) command.push("-referer", ref);

      // Filter out UA/Referer and join the rest for the -headers flag
      const other_headers = Object.entries(playback_headers)
        .filter(([k]) => !["user-agentx", "refererx"].includes(k.toLowerCase()))
        .map(([k, v]) => `${k}: ${v}`)
        // .map(([k, v]) => `${k}: ${v}\r\n`)
        .join("\r\n");

      if (other_headers) {
        command.push("-headers", other_headers + "\r\n");
      }

      /*
      const header_string = Object.entries(playback_headers)
        .map(([k, v]) => `${k}: ${v}`)
        .join("\r\n");
      command.push("-headers", header_string);
      */
    }
  }

  if (!file_mode) add_headers_if_needed();

  // add the input flag and URL
  command.push("-i", file_mode?.path || playback_url.href);

  if (_log) console.log("[PROBE CMD]", command, "\n");

  const proc = Bun.spawn(command, {
    stdout: "pipe",
    stderr: "pipe",
    signal: controller.signal
  });

  // 🚀 Use Promise.race to timeout faster
  const probePromise = (async () => {
    const [txtResponse, stderrResponse, exitCode] = await Promise.all([
      new Response(proc.stdout).text(),
      new Response(proc.stderr).text(),
      proc.exited
    ]);

    return { txt: txtResponse, stderr: stderrResponse, exitCode };
  })();

  const timeoutPromise = new Promise<never>((_, reject) => {
    setTimeout(() => reject(new Error("Probe timeout")), TIMEOUT_MS);
  });

  let result;
  try {
    result = await Promise.race([probePromise, timeoutPromise]);
  } catch (err) {
    clearTimeout(t);
    kill_controller();
    throw err;
  }

  clearTimeout(t);

  const { txt, stderr, exitCode } = result;

  if (exitCode !== 0) {
    clearTimeout(t);
    throw new Error(
      JSON.stringify({
        message: `Probe failed with code [${exitCode}]: ${stderr}`,
        code: exitCode,
        stderr: stderr
      })
    );
  }

  const metadata: FfprobeData = JSON.parse(txt);

  const streams = metadata.streams;

  let hasSubs = false;

  const audioStreams: any[] = [];
  const videoStreams: any[] = [];
  const subStreams: any[] = [];

  // Single pass through streams
  for (const stream of streams) {
    if (stream.codec_type === "video") {
      // if (!videoStream) videoStream = stream;
      videoStreams.push(stream);
    } else if (stream.codec_type === "audio") {
      // if (!audioStream) audioStream = stream;
      audioStreams.push(stream);
    } else if (stream.codec_type === "subtitle") {
      hasSubs = true;
      subStreams.push(stream);
    }
  }

  const videoStream = streams.find((s) => s.codec_type === "video");
  const audioStream = streams.find((s) => s.codec_type === "audio");

  // --- Track Selection Logic ---

  // Find English Audio or default to first audio (index 0 of audio type)
  const englishAudio = audioStreams.find((s) => s.tags?.language === "eng");
  const audioIndex = englishAudio?.index ?? audioStreams[0]?.index ?? 1;

  // Find English Subtitles or default to first subtitles
  const englishSub = subStreams.find((s) => s.tags?.language === "eng");
  const subIndex = englishSub?.index ?? subStreams[0]?.index ?? null;

  // Find 720p video or highest resolution
  const target720 = videoStreams.find(
    (s) => s.height === 720 || s.width === 1280
  );
  const bestVideo =
    target720 ||
    videoStreams.reduce(
      (best, current) =>
        (current.height || 0) > (best.height || 0) ? current : best,
      videoStreams[0]
    );

  const bestVideoIndex = bestVideo?.index;
  const bestVideoBox = bestVideo
    ? {
        height: bestVideo.height,
        width: bestVideo.width
      }
    : undefined;

  const probe_data: T_Probe = {
    videoCodec: videoStream?.codec_name || "none",
    audioCodec: audioStream?.codec_name || "none",
    hasSubs,
    duration: metadata.format.duration,
    size: metadata.format.size,
    format_name: metadata.format.format_name,
    audioIndex,
    subIndex,
    bestVideoIndex,
    bestVideoBox
  };

  return {
    probe_data,
    metadata
  };
}

async function F_build_ffmpeg_command_v1(arg0: {
  playback_headers?: Record<string, any>;
  playback_url: URL;
  context?: Context;
  is_net_src?: boolean;
  has_tcp_progress?: boolean;
  subtitles?: Record<string, any>[];
  probe_data: T_Probe;
  output_format: string;
  live: string;
}) {
  const {
    playback_url,
    context,
    is_net_src,
    has_tcp_progress,
    subtitles,
    probe_data,
    output_format,
    live
  } = arg0;

  let { playback_headers } = arg0;

  // -------------------------------
  // Logging options
  // -------------------------------
  const command: string[] = ["-hide_banner", "-loglevel", "info", "-stats"];

  // -------------------------------
  // Network reconnect options (network resilience)
  // -------------------------------
  if (is_net_src) {
    command.push("-reconnect", "1");
    command.push("-reconnect_streamed", "1");
    command.push("-reconnect_delay_max", "5");

    if (has_tcp_progress) {
      command.push("-timeout", "0");
      command.push("-rw_timeout", "0");
      command.push("-multiple_requests", "1");
    } else {
      command.push("-rw_timeout", (120 * 1_000_000).toString());
      command.push("-timeout", (120 * 1_000_000).toString());
    }
  }

  if (is_prod && FFMPEG_V === "latest") {
    command.push("-allowed_segment_extensions", "ALL");
    command.push("-allowed_extensions", "ALL");
    command.push("-extension_picky", "0");
    command.push("-protocol_whitelist", "file,http,https,tcp,tls,crypto");
    command.push("-strict", "experimental");
  }

  // -------------------------------
  // Playback headers
  // -------------------------------
  function add_headers_if_needed() {
    const ua = NS_misc.F_get_obj_kv({
      name: "User-Agent",
      obj: playback_headers
    });

    if (!ua) {
      try {
        // Generate a realistic desktop Chrome User-Agent
        const userAgent =
          UserAgent.random({ deviceCategory: "desktop" }) || new UserAgent();

        if (!playback_headers) {
          playback_headers = {};
        }

        playback_headers["User-Agent"] = userAgent.toString();
      } catch (err: any) {}
    }

    if (playback_headers && Object.keys(playback_headers).length > 0) {
      const ua = NS_misc.F_get_obj_kv({
        name: "User-Agent",
        obj: playback_headers
      });
      const ref = NS_misc.F_get_obj_kv({
        name: "Referer",
        obj: playback_headers
      });

      // if (ua) command.push("-user_agent", ua);
      // if (ref) command.push("-referer", ref);

      const other_headers = Object.entries(playback_headers)
        .filter(([k]) => !["user-agentx", "refererx"].includes(k.toLowerCase()))
        .map(([k, v]) => `${k}: ${v}`)
        // .map(([k, v]) => `${k}: ${v}\r\n`).join("")
        .join("\r\n");

      if (other_headers) {
        command.push("-headers", other_headers + "\r\n");
      }

      /*
      const header_string = Object.entries(playback_headers)
        .map(([k, v]) => `${k}: ${v}`)
        .join("\r\n");
      command.push("-headers", header_string);
      */
    }
  }

  add_headers_if_needed();

  command.push("-http_persistent", "0");

  /// -------------------------------
  // Input
  // -------------------------------
  command.push("-i", playback_url.href);

  // -------------------------------
  // Subtitle Logic
  // -------------------------------
  let has_native_subs = false;

  await handle_subtitles();

  async function handle_subtitles() {
    if (typeof probe_data.subIndex === "number") {
      // SOFT/NONE: Use 'copy' if possible to save CPU
      // Note: Browsers usually ignore these in a fragmented MP4 stream
      command.push("-map", `0:${probe_data.subIndex}`);
      command.push(
        "-c:s",
        output_format === "ts" ? "dvb_subtitle" : "mov_text"
      ); // "mov_text" MP4 compatible soft-sub format

      has_native_subs = true;
    }

    if (!(!has_native_subs && subtitles && subtitles.length)) return;

    let default_sub_index = subtitles.findIndex((xx) => xx.default);
    default_sub_index = default_sub_index < 0 ? 0 : default_sub_index;

    let burnt = false;
    const limit = 1;

    for (var i = 0; i < subtitles.length; i++) {
      if (i > limit) {
        break;
      }

      const subtitle = subtitles[i];

      const burn = subtitle.burn;
      const path = subtitle.file_path;
      const url = subtitle.url;
      let lang = subtitle.lang; // iso 639_2 prefeered
      const title = subtitle.title || subtitle.name;
      const is_default = default_sub_index === i;
      const subtitle_headers = subtitle.subtitle_headers;

      const n_ = i + 1;

      if (typeof lang === "string") {
        lang = lang.trim().toLowerCase();

        if (lang.length < 2) {
          lang = undefined;
        }

        if (lang.length > 3) {
          lang = lang.slice(0, 3);
        }
      } else {
        lang = undefined;
      }

      if (burn && path && (!burnt || is_default)) {
        // burn (local file only)
        const ext = path.extname(path).toLowerCase();
        if ([".vtt", ".srt", ".ass", ".ssa"].includes(ext)) {
          // Always normalize separators first
          let normalized = path
            .normalize(path)
            .replace(/\\/g, "/") // back-slashes → forward
            .replace(":", "\\:"); // escape the drive colon

          command.push("-i", path);
          command.push("-sub_charenc", "UTF-8");
          command.push("-vf", `subtitles='${normalized}'`);

          has_native_subs = true;

          burnt = true;

          continue;
        }
      }

      if (
        !url ||
        !NS_misc.isValidUrlFormat(url) ||
        typeof lang !== "string" ||
        !(lang.length > 0 && lang.length < 4)
      ) {
        continue;
      }

      if (subtitle_headers && Object.keys(subtitle_headers).length) {
        const headers_string = Object.entries(subtitle_headers)
          .map(([key, value]) => `${key}: ${value}`)
          .join("\r\n");
        command.push("-headers", headers_string);
      }

      command.push("-i", url);
      command.push("-map", `${i}:0`);
      command.push(
        `-c:s:${i}`,
        output_format === "ts" ? "dvb_subtitle" : "mov_text"
      );
      command.push(`-metadata:s:s:${i}`, `language=${lang}`);
      if (title) {
        command.push(`-metadata:s:s:${i}`, `title=${title}`);
      }
      if (is_default) {
        command.push(`-disposition:s:${i}`, `default`);
      }
    }
  }

  // -------------------------------
  // Video Audio Logic
  // -------------------------------
  if (
    probe_data.videoCodec === "h264" &&
    probe_data.audioCodec === "aac" &&
    !has_native_subs &&
    (output_format === "mp4" || output_format === "ts") &&
    typeof probe_data.audioIndex !== "number"
  ) {
    command.push("-c:v", "copy", "-c:a", "copy", "-bsf:a", "aac_adtstoasc");
  } else {
    if (typeof probe_data.bestVideoIndex === "number") {
      command.push("-map", `0:${probe_data.bestVideoIndex}?`);
    } else {
      if (typeof probe_data.audioIndex === "number") {
        command.push("-map", "0:v:0?");
      }
    }

    // command.push("-c:v", "libx264");
    command.push("-c:v", hw_encoder || "libx264");
  }

  if (typeof probe_data.audioIndex === "number") {
    command.push("-map", `0:${probe_data.audioIndex}?`);
  }

  command.push("-tune", "zerolatency");
  command.push("-crf", "23");
  command.push("-preset", live === "stream" ? "ultrafast" : "medium");
  command.push("-pix_fmt", "yuv420p");
  command.push("-c:a", "aac");
  command.push("-b:a", "256k");

  command.push("-max_interleave_delta", "0");

  // -------------------------------
  // Output format
  // -------------------------------
  command.push("-f", output_format === "ts" ? "mpegts" : output_format);

  // -------------------------------
  // Flags
  // -------------------------------
  command.push("-avoid_negative_ts", "make_zero");
  command.push("-fflags", "+genpts+nobuffer");
  // command.push("-fflags", "+genpts+igndts"); // Generate PTS and ignore invalid DTS

  if (live === "stream") {
    // command.push("-use_wallclock_as_timestamps", "1"); // Use wallclock for live streams
  }

  command.push("-fps_mode", "passthrough"); // Don't duplicate/drop frames for timestamp sync

  if (is_net_src) {
    command.push("-movflags", "frag_keyframe+empty_moov+default_base_moof");
  } else {
    command.push("-movflags", "+faststart");
  }

  return command;
}

async function F_build_ffmpeg_command_v2(arg0: {
  playback_headers?: Record<string, any>;
  playback_url: URL;
  context?: Context;
  is_net_src?: boolean;
  has_tcp_progress?: boolean;
  subtitle?: Record<string, any>;
  probe_data: T_Probe;
  output_format: string;
  live: string;
}) {
  const {
    playback_headers,
    playback_url,
    context,
    is_net_src,
    has_tcp_progress,
    subtitle,
    probe_data,
    output_format,
    live
  } = arg0;

  const command = fluent_ffmpeg();

  // -------------------------------
  // Logging options
  // -------------------------------
  command
    .addOption("-hide_banner")
    .addOption("-loglevel", "info")
    .addOption("-stats");

  // -------------------------------
  // Network reconnect options (network resilience)
  // -------------------------------
  if (is_net_src) {
    command.addOption("-reconnect", "1");
    command.addOption("-reconnect_streamed", "1");
    command.addOption("-reconnect_delay_max", "5");

    if (has_tcp_progress) {
      command.addOption("-timeout", "0");
      command.addOption("-rw_timeout", "0");
      command.addOption("-multiple_requests", "1");
    } else {
      command.addOption("-rw_timeout", (120 * 1_000_000).toString()); // 1 second=1,000,000 microseconds
      command.addOption("-timeout", (120 * 1_000_000).toString()); // 1 second=1,000,000 microseconds
    }
  }

  if (is_prod && FFMPEG_V === "latest") {
    command.addOption("-allowed_segment_extensions", "ALL");
    command.addOption("-allowed_extensions", "ALL");
    command.addOption("-extension_picky", "0");
    command.addOption("-protocol_whitelist", "file,http,https,tcp,tls,crypto");
    command.addOption("-strict", "experimental");
  }

  // -------------------------------
  // Playback headers
  // -------------------------------
  if (playback_headers && Object.keys(playback_headers).length > 0) {
    const header_string = Object.entries(playback_headers)
      .map(([k, v]) => `${k}: ${v}`)
      .join("\r\n");

    command.addOption("-headers", header_string);
  }

  command.addOption("-http_persistent", "0");

  // -------------------------------
  // Input
  // -------------------------------
  command.input(playback_url.href);

  // -------------------------------
  // Subtitle Logic
  // -------------------------------
  let has_native_subs = false;

  if (typeof probe_data.subIndex === "number") {
    // SOFT/NONE: Use 'copy' if possible to save CPU
    // Note: Browsers usually ignore these in a fragmented MP4 stream
    command.addOption("-map", `0:${probe_data.subIndex}`);
    command.addOption(
      "-c:s",
      output_format === "ts" ? "dvb_subtitle" : "mov_text"
    ); // "mov_text" MP4 compatible soft-sub format

    has_native_subs = true;
  }

  await (async () => {
    if (!(!has_native_subs && subtitle)) return;

    const burn = subtitle.burn;
    const path = subtitle.path;
    const url = subtitle.url;
    const lang = subtitle.lang;
    const name = subtitle.name;
    const subtitle_headers = subtitle.subtitle_headers;

    if (burn && path) {
      // burn (local file only)
      const ext = path.extname(path).toLowerCase();
      if ([".vtt", ".srt", ".ass", ".ssa"].includes(ext)) {
        // Always normalize separators first
        let normalized = path
          .normalize(path)
          .replace(/\\/g, "/") // back-slashes → forward
          .replace(":", "\\:"); // escape the drive colon

        command.addOption("-sub_charenc", "UTF-8");
        command.addOption("-i", path);
        command.addOption("-vf", `subtitles='${normalized}'`);

        has_native_subs = true;

        return;
      }
    }

    if (
      !url ||
      !NS_misc.isValidUrlFormat(url) ||
      typeof lang !== "string" ||
      !(lang.trim().length > 0 && lang.trim().length < 4)
    ) {
      return;
    }

    if (subtitle_headers && Object.keys(subtitle_headers).length) {
      const headers_string = Object.entries(subtitle_headers)
        .map(([key, value]) => `${key}: ${value}`)
        .join("\r\n");
      command.addOption("-headers", headers_string);
    }

    command.addOption("-metadata:s:s:0", `language=${lang.trim()}`);
    command.addOption(
      "-c:s",
      output_format === "ts" ? "dvb_subtitle" : "mov_text"
    );

    command.addOption("-i", url);
  })();

  // -------------------------------
  // Video Audio Logic
  // -------------------------------
  if (
    probe_data.videoCodec === "h264" &&
    probe_data.audioCodec === "aac" &&
    !has_native_subs &&
    (output_format === "mp4" || output_format === "ts") &&
    typeof probe_data.audioIndex !== "number"
  ) {
    command.addOption(
      "-c:v",
      "copy",
      "-c:a",
      "copy",
      "-bsf:a",
      "aac_adtstoasc"
    );
  } else {
    if (typeof probe_data.bestVideoIndex === "number") {
      command.addOption("-map", `0:${probe_data.bestVideoIndex}`);
    } else {
      if (typeof probe_data.audioIndex === "number") {
        command.addOption("-map", "0:v:0");
      }
    }

    command.addOption("-c:v", "libx264");
  }

  if (typeof probe_data.audioIndex === "number") {
    command.addOption("-map", `0:${probe_data.audioIndex}`);
  }

  command.addOption("-tune", "zerolatency"); // tells the encoder to minimize the delay between capturing a frame and outputting it
  command.addOption("-crf", "23");
  command.addOption("-preset", live === "stream" ? "ultrafast" : "medium");
  command.addOption("-pix_fmt", "yuv420p");
  command.addOption("-c:a", "aac");
  command.addOption("-b:a", "256k");

  command.addOption("-max_interleave_delta", "0");

  // -------------------------------
  // Output format
  // -------------------------------
  command.format(output_format === "ts" ? "mpegts" : output_format);

  // -------------------------------
  // Flags
  // -------------------------------
  command.addOption("-avoid_negative_ts", "make_zero");
  command.addOption("-fflags", "+genpts+nobuffer");
  // command.addOption("-fflags", "+genpts+igndts"); // Generate PTS and ignore invalid DTS

  if (live === "stream") {
    // command.addOption("-use_wallclock_as_timestamps", "1"); // Use wallclock for live streams
  }

  command.addOption("-fps_mode", "passthrough"); // Don't duplicate/drop frames for timestamp sync

  if (is_net_src) {
    command.addOption(
      "-movflags",
      "frag_keyframe+empty_moov+default_base_moof"
    );
  } else {
    command.addOption("-movflags", "+faststart");
  }

  return command;
}

async function F_build_ffmpeg_command_v3(arg0: {
  playback_headers?: Record<string, any>;
  playback_url: URL;
  playback_type?: string;
  context?: Context;
  is_net_src?: boolean;
  has_tcp_progress?: boolean;
  subtitles?: Record<string, any>[];
  probe_data: T_Probe;
  output_format: "ts" | "mp4" | "mkv";
  live: string;
  file_mode?: boolean;
  re_encode_audio?: boolean;
}) {
  const {
    playback_url,
    context,
    is_net_src,
    has_tcp_progress,
    subtitles,
    probe_data,
    output_format,
    live,
    playback_type,
    file_mode,
    re_encode_audio
  } = arg0;

  let { playback_headers } = arg0;

  // -------------------------------
  // Logging options
  // -------------------------------
  const command: string[] = ["-hide_banner", "-loglevel", "info", "-stats"];

  // -------------------------------
  // ADD THREAD LIMIT (Crucial for 0.25 vCPU)
  // -------------------------------
  // if (!CPU_0V1 || `${CPU_0V1}` !== "1") command.push("-threads", "1");

  // -------------------------------
  // Network reconnect options (network resilience)
  // -------------------------------
  const timeoutVal = has_tcp_progress ? "0" : (80 * 1_000_000).toString();

  if (is_net_src) {
    command.push("-reconnect", "1");
    command.push("-reconnect_streamed", "1");
    command.push("-reconnect_delay_max", "20");
    command.push("-reconnect_on_network_error", "1");
    command.push("-reconnect_on_http_error", "429,500,502,503,504");

    // command.push("-rw_timeout", timeoutVal, "-timeout", timeoutVal);
    // command.push("-rw_timeout", timeoutVal);
    command.push("-rw_timeout", timeoutVal, "-timeout", timeoutVal);

    if (has_tcp_progress) {
      command.push("-multiple_requests", "1");
    }
  }

  if (is_prod && FFMPEG_V === "latest") {
    command.push("-allowed_segment_extensions", "ALL");
    command.push("-allowed_extensions", "ALL");
    command.push("-extension_picky", "0");
    command.push("-protocol_whitelist", "file,http,https,tcp,tls,crypto");
    command.push("-strict", "experimental");
    // command.push("-demuxer", "hls");
  }

  // -------------------------------
  // MAIN VIDEO INPUT (Input 0)
  // -------------------------------
  function add_headers_if_needed() {
    const ua = NS_misc.F_get_obj_kv({
      name: "User-Agent",
      obj: playback_headers
    });

    if (!ua) {
      try {
        const userAgent =
          UserAgent.random({ deviceCategory: "desktop" }) || new UserAgent();

        if (!playback_headers) {
          playback_headers = {};
        }

        playback_headers["User-Agent"] = userAgent.toString();
      } catch (err: any) {}
    }

    if (playback_headers && Object.keys(playback_headers).length > 0) {
      const ua = NS_misc.F_get_obj_kv({
        name: "User-Agent",
        obj: playback_headers
      });
      const ref = NS_misc.F_get_obj_kv({
        name: "Referer",
        obj: playback_headers
      });

      if (ua) command.push("-user_agent", ua);
      if (ref) command.push("-referer", ref);

      const other_headers = Object.entries(playback_headers)
        .filter(([k]) => !["user-agent", "referer"].includes(k.toLowerCase()))
        .map(([k, v]) => `${k}: ${v}`)
        .join("\r\n");

      if (other_headers) {
        command.push("-headers", other_headers + "\r\n");
      }
    }
  }

  add_headers_if_needed();

  // command.push("-http_multiple", "0");
  // command.push("-analyzeduration", "10M");
  // command.push("-probesize", "10M");
  // command.push("-seg_max_retry", "5");
  // command.push("-max_reload", "100");

  command.push("-fflags", "+discardcorrupt+genpts+nobuffer");
  // command.push("-err_detect", "ignore_err");

  if (
    playback_type === "hls" ||
    (typeof playback_type === "string" && playback_type.includes("hls")) ||
    (typeof probe_data.format_name === "string" &&
      probe_data.format_name.includes("hls"))
  ) {
    command.push("-http_persistent", "1");
  }

  command.push("-i", playback_url.href);

  // -------------------------------
  // SUBTITLE INPUTS (Input 1...N)
  // -------------------------------
  const all_subs = Array.isArray(subtitles) ? subtitles : [];

  const valid_external_subs = (() => {
    const limit = 4;
    let soft_subs = all_subs.filter((s) => s.url && !s.burn);

    return get_filtered_subs({ limit, subs: soft_subs });
  })();

  const valid_bun_subs = (() => {
    const limit = 1;
    let burn_subs = all_subs.filter((s) => s.path && s.burn);

    return get_filtered_subs({ limit, subs: burn_subs });
  })();

  function get_filtered_subs(arg0: { limit: number; subs: any[] }) {
    const { limit, subs: originalSubs } = arg0;

    let subs = [...originalSubs];

    if (!limit || !(subs.length > limit)) return subs;

    const defaultIdx = subs.findIndex((s) => {
      const hasValidUrl =
        typeof s?.url === "string" && NS_misc.isValidUrlFormat(s.url);

      return hasValidUrl && s.default;
    });

    let defaultSub = null;

    if (defaultIdx > -1) {
      [defaultSub] = subs.splice(defaultIdx, 1);
    }

    const englishRegex = /\b(en|eng|english)\b/i;

    const englishSubs = [];
    const otherSubs = [];

    for (const s of subs) {
      const matchesEnglish = [s.lang, s.title, s.name].some(
        (field) => typeof field === "string" && englishRegex.test(field)
      );

      const hasValidUrl =
        typeof s?.url === "string" && NS_misc.isValidUrlFormat(s.url);

      if (!hasValidUrl) continue;

      if (matchesEnglish) {
        englishSubs.push(s);
      } else {
        otherSubs.push(s);
      }
    }

    const result = [];
    if (defaultSub) result.push(defaultSub);

    let combined = [...result, ...englishSubs, ...otherSubs];

    if (limit) {
      combined = combined.slice(0, limit);
    }

    return combined;
  }

  for (const sub of valid_external_subs) {
    const subtitle_headers = sub.subtitle_headers;
    const url = sub.url;

    if (subtitle_headers && Object.keys(subtitle_headers).length) {
      const h_str = Object.entries(subtitle_headers)
        .map(([k, v]) => `${k}: ${v}`)
        .join("\r\n");
      command.push("-headers", h_str);
    }

    command.push("-i", url);
  }

  // ---------------------------------------------------------
  // MAPPING SECTION (The "Output" configuration starts here)
  // ---------------------------------------------------------
  const is_burning =
    valid_bun_subs &&
    Array.isArray(valid_bun_subs) &&
    valid_bun_subs.length > 0;

  const must_re_encode =
    valid_bun_subs?.length ||
    probe_data.videoCodec !== "h264" ||
    probe_data.audioCodec !== "aac" ||
    typeof probe_data.subIndex === "number" ||
    (output_format !== "mp4" && output_format !== "ts");

  /* VIDEO MAPPING */
  if (typeof probe_data.bestVideoIndex === "number") {
    command.push("-map", `0:${probe_data.bestVideoIndex}?`);
  } else {
    command.push("-map", "0:v:0?");
  }

  if (must_re_encode) {
    command.push("-c:v", hw_encoder || "libx264");

    if (is_burning && valid_bun_subs[0].path) {
      const safePath = valid_bun_subs[0].path
        .replace(/\\/g, "/")
        .replace(/:/g, "\\:");
      command.push("-vf", `subtitles='${safePath}'`);
    }
  } else {
    command.push("-c:v", "copy");
  }

  /* AUDIO MAPPING */
  if (typeof probe_data.audioIndex === "number") {
    command.push("-map", `0:${probe_data.audioIndex}?`);
  } else {
    command.push("-map", "0:a:0");
  }

  if (must_re_encode || re_encode_audio) {
    command.push("-c:a", "aac", "-b:a", "256k");
    // command.push("-async", "1");
    command.push("-af", "loudnorm=I=-14:TP=-1.5:LRA=11,aresample=async=1");
  } else {
    command.push("-c:a", "copy", "-bsf:a", "aac_adtstoasc");
  }

  /* SOFT SUBTITLE MAPPING */
  let out_sub_idx = 0;
  let has_assigned_default = false;

  const sub_claims_default =
    valid_external_subs.some((s) => s.default) ||
    typeof probe_data.subIndex === "number";

  // Native Subs (from Input 0)
  if (typeof probe_data.subIndex === "number") {
    command.push("-map", `0:${probe_data.subIndex}`);
    command.push(
      `-c:s:${out_sub_idx}`,
      output_format === "ts" ? "dvb_subtitle" : "mov_text"
    );

    command.push(`-disposition:s:${out_sub_idx}`, "default");
    has_assigned_default = true;
    out_sub_idx++;
  }

  // External Subs (starting from Input 1)
  for (let i = 0; i < valid_external_subs.length; i++) {
    const sub = valid_external_subs[i];
    const input_idx = i + 1; // Because video is 0

    const title = sub.title || sub.name;
    const is_default = sub.default;
    let lang = (sub.lang || "und").trim();
    lang = lang.slice(0, 3).toLowerCase();

    const should_be_default =
      !has_assigned_default && (is_default || (!sub_claims_default && i === 0));

    command.push("-map", `${input_idx}:0`);
    command.push(
      `-c:s:${out_sub_idx}`,
      output_format === "ts" ? "dvb_subtitle" : "mov_text"
    );

    // Metadata
    command.push(`-metadata:s:s:${out_sub_idx}`, `language=${lang}`);
    if (title) {
      command.push(`-metadata:s:s:${out_sub_idx}`, `title=${title}`);
    }

    // Default Toggle
    if (should_be_default) {
      command.push(`-disposition:s:${out_sub_idx}`, "default");
      has_assigned_default = true;
    } else {
      command.push(`-disposition:s:${out_sub_idx}`, "0");
    }

    out_sub_idx++;
  }

  const use_ultrafast = live === "stream" || valid_bun_subs.length;

  /* ENCODING & TUNING */
  if (live === "stream") {
    command.push("-tune", "zerolatency");
  }

  // if (must_re_encode) {
    if(hw_encoder.includes("h264_qsv")) {
      command.push("-preset", use_ultrafast ? "7" : "7"); // QSV uses numbers: 7 is fastest speed (ultrafast), 4 is balanced (medium)
    } else {
      command.push("-crf", "23");
      command.push("-preset", use_ultrafast ? "ultrafast" : "ultrafast"); // ultrafast veryfast faster medium
    }
  // }
  if (must_re_encode) command.push("-pix_fmt", "yuv420p");
  command.push("-max_interleave_delta", "0");

  /* OUTPUT FORMAT & FLAGS */

  if (live === "stream") {
    command.push("-f", "ismv");
  } else {
    command.push("-f", output_format === "ts" ? "mpegts" : output_format);
  }

  command.push("-avoid_negative_ts", "make_zero");

  if (live === "stream") {
    // command.push("-use_wallclock_as_timestamps", "1");
  }

  if (file_mode) {
    // command.push("-fps_mode", "cfr"); // passthrough cfr
    command.push("-max_muxing_queue_size", "9999");
  } else {
    command.push("-fps_mode", "passthrough");
  }

  if (is_net_src && !file_mode) {
    // command.push("-movflags", "frag_keyframe+empty_moov+default_base_moof");
    command.push("-movflags", "frag_keyframe+dash+delay_moov");
  } else {
    command.push("-movflags", "+faststart");
  }

  return command;
}

function F_stderr_data_read(arg0: { output: string }) {
  const { output } = arg0;
  let duration = 0;
  let current_time = 0;
  let current_size_bytes = 0;
  let progress = 0;

  // Extract duration with flexible whitespace
  const durationMatch = output.match(
    /Duration:\s*(\d{2}):(\d{2}):(\d{2}\.\d{2})/
  );
  if (durationMatch) {
    const [, hours, minutes, seconds] = durationMatch;
    duration =
      parseInt(hours) * 3600 + parseInt(minutes) * 60 + parseFloat(seconds);
  }

  // Extract current time with flexible whitespace
  const timeMatch = output.match(/time\s*=\s*(\d{2}):(\d{2}):(\d{2}\.\d{2})/);
  if (timeMatch) {
    const [, hours, minutes, seconds] = timeMatch;
    current_time =
      parseInt(hours) * 3600 + parseInt(minutes) * 60 + parseFloat(seconds);
  }

  // Extract size with flexible whitespace (captures both 'size' and 'Lsize')
  const sizeMatch = output.match(
    /[Ll]?size\s*=\s*(\d+(?:\.\d+)?)\s*([kmgtKMGT]?[bB]?)/
  );
  if (sizeMatch) {
    const [, sizeValue, unit] = sizeMatch;
    let sizeInBytes = parseFloat(sizeValue);

    // Convert to bytes based on unit
    const unitLower = unit.toLowerCase();
    switch (unitLower) {
      case "kb":
        sizeInBytes *= 1024;
        break;
      case "mb":
        sizeInBytes *= 1024 * 1024;
        break;
      case "gb":
        sizeInBytes *= 1024 * 1024 * 1024;
        break;
      case "tb":
        sizeInBytes *= 1024 * 1024 * 1024 * 1024;
        break;
      // 'b' or no unit means bytes already
    }

    current_size_bytes = Math.round(sizeInBytes);
  }

  // Calculate and log progress if we have the necessary data
  if (duration && current_time) {
    progress = Math.min(
      parseFloat(((current_time / duration) * 100).toFixed(2)),
      100
    );

    let progress_info = `${progress}%`;
    if (current_size_bytes !== undefined) {
      // Format size for display
      const formatSize = (bytes: number): string => {
        if (bytes < 1024) return `${bytes}B`;
        if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)}KB`;
        if (bytes < 1024 * 1024 * 1024)
          return `${(bytes / (1024 * 1024)).toFixed(1)}MB`;
        return `${(bytes / (1024 * 1024 * 1024)).toFixed(1)}GB`;
      };

      // progress_info += `, size = ${formatSize(current_size_bytes)}`;
    }
  }

  return {
    video_duration: duration,
    current_out_time: current_time,
    current_size_bytes
  };
}

function F_format_duration(seconds?: number): string {
  if (typeof seconds !== "number") {
    return "";
  }

  if (isNaN(seconds) || seconds < 0) return "0:00";

  const hrs = Math.floor(seconds / 3600);
  const mins = Math.floor((seconds % 3600) / 60);
  const secs = Math.floor(seconds % 60);

  let data = "";

  if (hrs > 0) {
    data = `${hrs}:${mins.toString().padStart(2, "0")}:${secs
      .toString()
      .padStart(2, "0")}`;
  } else {
    data = `${mins}:${secs.toString().padStart(2, "0")}`;
  }

  return data;
}

function F_format_size(bytes?: number) {
  if (typeof bytes !== "number") {
    return;
  }

  if (bytes < 1024) return `${bytes} B`;
  if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(2)} KB`;
  if (bytes < 1024 * 1024 * 1024)
    return `${(bytes / (1024 * 1024)).toFixed(2)} MB`;
  return `${(bytes / (1024 * 1024 * 1024)).toFixed(2)} GB`;
}

export const NS_ffmpeg = {
  fluent_ffmpeg,
  ffmpeg_path,
  ffprobe_path,
  TIMEOUT_MS,
  PROBE_TIMEOUT_MS,
  F_probe_v1,
  F_probe_v2,
  F_build_ffmpeg_command_v1,
  F_build_ffmpeg_command_v2,
  F_build_ffmpeg_command_v3,
  F_format_duration,
  F_format_size,
  F_stderr_data_read,
  get_hardware_encoder
};